bitkeeper revision 1.1003.1.1 (40daac7c6-RMqdy1PiSH_fSWwxWf9A)

master Makefile modified to build each the dom0 and unprivileged 
xenlinux kernels in different build trees. Also, the "-xen[0U]" tag
is reflected in the kernel version name. This means that different 
modules will need to be built for each, which is less convenient for 
an expert, but probably less confusing for most users.

README

@@ -53,9 +53,10 @@ Xen for pretty much any other architecture as x86 is particularly
 tricky to handle. A good description of Xen's design, implementation 
 and performance is contained in our October 2003 SOSP paper, available
 at http://www.cl.cam.ac.uk/netos/papers/2003-xensosp.pdf
+[update: work to port Xen to x86_64 and IA64 is underway]
 
-We have worked on porting 4 different operating systems to run
-on Xen: Linux 2.4/2.6, Windows XP, NetBSD and FreeBSD.
+Five different operating systems have been ported to run on Xen: 
+Linux 2.4/2.6, Windows XP, NetBSD, FreeBSD and Plan 9.
 
 The Linux 2.4 port (currently Linux 2.4.26) works very well -- we
 regularly use it to host complex applications such as PostgreSQL,
@@ -66,12 +67,12 @@ virtual CPU architecture that we call xen-x86.
 
 NetBSD has been ported to Xen by Christian Limpach, and will hopefully
 soon become part of the standard release. Work on a FreeBSD port has
-been started by Kip Macy, and we hope to see this complete for the 1.3
-release.
+been started by Kip Macy, and we hope to see this complete for the 2.0
+release. Ron Minnich has been working on Plan 9.
 
 The Windows XP port is nearly finished. It's running user space
 applications and is generally in pretty good shape thanks to some hard
-work by the team over the summer.  Of course, there are issues with
+work by a team over the summer.  Of course, there are issues with
 releasing this code to others.  We should be able to release the
 source and binaries to anyone that has signed the Microsoft academic
 source license, which these days has very reasonable terms. We are in
@@ -96,6 +97,20 @@ We've successfully booted over 128 copies of Linux on the same machine
 (a dual CPU hyperthreaded Xeon box) but we imagine that it would be
 more normal to use some smaller number, perhaps 10-20.
 
+A common question is "how many virtual machines can I run on hardware
+xyz?". The answer is very application dependent, but the rule of thumb
+is that you should expect to be able to run the same workload under
+multiple guest OSes that you could run under a single Linux instance,
+with an additional overhead of a few MB per OS instance.
+
+One key feature in this new release of Xen is `live migration'. This
+enables virtual machines instances to be dynamically moved between
+physical Xen machines, with typical downtimes of just a few tens of
+milliseconds. This is really useful for admins that want to take a
+node down for maintenance, or to load balance a large number of
+virtual machines across a cluster.
+
+
 
 Hardware support
 ================
@@ -177,9 +192,13 @@ downloads page:  http://www.cl.cam.ac.uk/netos/xen/downloads/
 Using the domain control tools
 ==============================
 
-README.CD contains some example invocations.
+Before starting domains you'll need to start the node management
+daemon: "xend start". 
 
-See example Python scripts in tools/examples/ and the associated README.
+The primary tool for starting and controlling domains is "xm". 
+"xm help <cmd>" will tell you how to use it.
+
+README.CD contains some example invocations.
 
 Further documentation is in docs/ (e.g., docs/Xen-HOWTO), and also in